1. Field of the Invention
The present invention relates to a self-contained fuel cell and a cartridge therefor. The invention also relates to a refillable fuel cell and a refilling device.
2. Discussion of Background Information
An electrochemical fuel cell is a device that converts the energy of a chemical reaction into electricity. Among the advantages that fuel cells have over other sources of electrical energy are a high efficiency and environmental friendliness. Although fuel cells are increasingly gaining acceptance as electrical power sources, there are technical difficulties that prevent the widespread use of fuel cells in many applications, especially mobile and portable applications. A fuel cell produces electricity by bringing a fuel into contact with a catalytic anode while bringing an oxidant into contact with a catalytic cathode. When in contact with the anode, the fuel is oxidized at catalytic centers to produce electrons. The electrons travel from the anode to the cathode through an electrical circuit connecting the electrodes. Simultaneously, the oxidant is catalytically reduced at the cathode, consuming the electrons generated at the anode. Mass balance and charge balance are preserved by the corresponding production of ions at either the cathode or the anode and the diffusion of these ions to the other electrode through an electrolyte with which the electrodes are in contact. As the fuel cell produces electricity, the liquid fuel and the electrolyte are gradually exhausted of their useful components. Consequently, fresh liquid fuel must continuously be supplied to known fuel cells. In other words, at least during operation, liquid (and other) fuel cells are open systems, because they depend on the constant supply of fresh fuel (and fresh electrolyte) from the exterior. It would be very desirable to have available a fuel cell that is capable of being operated in a substantially sealed state, similar to a battery. It would also be desirable to be able to reuse this sealed fuel cell after the liquid fuel and/or the liquid electrolyte are exhausted.